Re: [RFC 0/3] drivers: Add an API to read device specific config data

From: Moritz Fischer
Date: Mon Feb 27 2017 - 17:28:39 EST


Hi all,

On Mon, Feb 27, 2017 at 12:42 PM, Boris Brezillon
<boris.brezillon@xxxxxxxxxxxxxxxxxx> wrote:
> +Moritz
>
> Hi Alban,
>
> On Mon, 27 Feb 2017 21:28:09 +0100
> Alban <albeu@xxxxxxx> wrote:
>
>> Hi all,
>>
>> while looking at adding OF support for the ath9k driver I had the problem of
>> reading the EEPROM data. On the SoC platforms this data is stored in an SPI
>> flash along with a few other things. In OpenWRT/LEDE this data is read from
>> the board init code using the fact that the flash is (normaly) readable from
>> a memory map. A bit too hackish for my taste.
>>
>> This is just one example, there is various other similar cases, mostly with
>> MAC addresses. I thought it would be nicer if we had a clean API for this,
>> similar to the firmware API but per device instance instead of beeing per
>> driver. The device driver wouldn't have to care where the data is stored,
>> they just request it and the backend take care of reading the EEPROM, MTD
>> or whatever is used on the board.
>>
>> This series implement such an API along with an implementation for MTD
>> devices and a use in the ath9k driver. As this is an RFC I didn't yet
>> write the OF binding documentation, that will come later if the feedback
>> is positive.
>
> What you're looking for already exists and it's called nvmem[1]. Some
> work has been done to expose MTD partitions as nvmem cells [2], but
> it's never been finished.
> Can you please finish Moritz implementation instead of creating a new
> API?

Whoops ... this totally fell off my radar (project got axed for $REASONS).
I could potentially take another look at this this weekend, otherwise I'm
happy to review whatever you come up with Alban.

Cheers,

Moritz